Stacking device



Dec. 1, 1964 F. A. DAVIS, JR., ETAL 3,159,399

STACKING DEVICE 4 Sheets-Sheet 1 Filed Dec. 7, 1961 1NVEN.TOR$. .fid/lr/JA flaw/1.51:1): AZ BY Jury/7 Ffidlilizr 14 e A Tran/ways.

Dec. 1, 1964 F. A- DAVIS, JR.. ETAL 3,159,399

STACKING DEVICE Filed Dec. 7, 1961 4 Sheets-Sheet 3 INVENTORS. [7271101314. flavmyf': & BY Jwgab 1. fifiliiitl 'y,

Dec. 1, 1964 F. A. DAVIS, JR ETAL 3,159,399

STACKING DEVICE Filed Dec. 7, 1961 4 Sheets-Sheet 4 INVENTORS. Fran-i292. flaw; J1: &. BY Janyfi if Flax/fizzy,

@ujs @J A 770/7/VEV5.

United Sates atent 3,l59,3% Fatented Dec. 1, 1%64 fifice 3,159,399 STACKING DEVME Francis A. Davis, n, Lansdale, and .loseph F. Flannel-y,

lvinyfair, P2,, assignors to Paramount Packaging Corporation, Chaifont, Pa, a corporation of Pennsylvania Filed Dec. 7, 1961, Ser. No. 157,684

7 Claims. (Cl. 27l89) his application relates generally to stacking devices and particularly to an improved device for stacking sheet material.

Retail stores, for example, supermarkets, are commonly equipped with machines which are used for handling plastic bags in which various items sold by such stores are conveniently packaged. The bags are delivered to the store by the manufacturer pre-stacked and mounted upon wire hoops or wickets ready to be loaded in the machine. The bags are made of very thin plastic sheet material, which has practically no body, in consequence of which they are difficult to handle. Yet they must be stacked accurately so that the holes or slits provided in the bags for receiving the legs of the wicket are aligned. Accordingly, a principal object of the invention is to provide an improved device for stacking plastic bags to facilitate mounting them upon a wicket.

Another object of the invention is to provide such a device which when arranged for stacking bags of one size may be conveniently rearranged for stacking bags of a different size.

Other objects of the invention will become apparent when the following description is read with reference to the accompanying drawings, in which:

PEG. 1 is a perspective view or" the stacking device;

FIG. 2 is an enlarged fragmentary perspective view of the stacking tray, as indicated by 11 in FIG. 1;

FIG. 3 is an enlarged fragmentary vertical section, as indicated by line HIIII in FIG. 2;

FIG. 4 is a plan view of the stacking tray;

FIG. 5 is a vertical section on line V-V of FIG. 4, showing some bags stacked in the tra FlG. 6 is a vertical section on line IL-VI of FIG. 5, showing some bags stacked in the tray;

FIG. 7 is an enlarged section on line Vii-Vii in FIG. 6;

FIG. 8 is a view looking upwardly as indicated by line VllL-Vlll in FIG. 7'.

P16. 9 is an enlarged perspective view of the stacking tray,,showing a stack of bags about to be removed therefrom;

FTG. 10 is a perspective view of the base section of the stacking tray; and

1G. 11 is a perspective view of the upper section of the stacking tray.

Referring particularly to FIG. 1, apparatus constructed in accordance with the invention comprises a wheeled frame, generally designated ill, provided with a horizontally extending plate 12 mounted upon four wheels 14. Extending upwardly from the four corners of the. plate 12 are tubular posts 16, which slidably receive four legs 18 of a table having a top 24 The legs 18 are secured by thumb screws 22 against sliding in the posts 16.

Mounted upon the plate 12 is a conventional jack mechanism 24 from which a rod 26 extends upwardly for connection to the bottom of the table top Ztl. To vary the elevation of the table top 2%, the screws 22 are loosened and the jack 24 is operated to raise or lower the table to the desired position, whereupon the screws 22 are retightened.

Mounted upon the table top 29 is a conventional vibrator mechanism, generally designated 28, and means for controlling the same, generally designated 30.

The stacking tray, generally designated 32, comprises a base section, generally designated 34. The section 34- includes a horizontally extending rectangular wooden plate 36. An upright wooden rail 38 extends across the foot end of plate 36 and is provided with an abutment surface 39 and with a series of openings ill. An upright wooden rail 42 extends along one side of the plate 36. The end of the rail 38 proximate the rail 42 is set back a substantial distance from the side of the plate 36 which mounts the rail as. The ends of the rail 42 are set back a substantial distance respectively from the head and foot ends of the plate 36.

Mounted upon the rail 42 is a metal plate provided with a flange 44 overlying the top of the rail 42 and overhanging the inner side thereof, being secured to the rail 42 by screws, designated 46. From the flange 44 depends a flange 47 bent to provide a guide surface 43 sloping downwardly and outwardly toward the rail 42, and to provide an abutment surface 49 extending downwardly along the inner side of the rail 42 to the plate 3d. The sloping flange part is provided with a series of openings 5%.

Embedded in the top of the plate 36 are a pair of metal strips 52 secured in position by screws 54. The upper surfaces of the strips 52 are fiush with the upper surface of the plate 36. Underlying the plate 36 are a bar 56 and a bar 58 affixed, as by screws 60, to the plate 36. Depending from the plates 56 and 58 and affixed thereto, as by welding 63, is a rod 62. Afiixed to the lower end portion of the rod 62 is a ball 64. Underlying the ball 64 is a stud 66 affixed to the vibrator 28, as by screws 58. The stud 66 is provided with a socket '79 in which nests the lower portion of the ball 64. Threaded onto the stud es is a cap '72, which is rounded, as at 7 3, for being seated upon the ball 64. Extending downwardly into the cap is an axially tapered opening 35'.

The stacking tray 32 also comprises an upper section, generally designated 76. The section '76 includes a horizontally extendirn plate 73, the corners of which are recessed, as at 89. A metal plate 82 extends across the head end of the plate 78, being secured thereto by screws, designated 84. The plate 32 is set back from one side of the plate 78 and is provided with openings 86. The inner face of the plate 82 affords a guide surface 83.

Afdxed to one side of the plate 73, as by screws 92, is a metal plate An upper marginal portion of the plate 9t is ofiset outwardly, as at 94-. The inner face of the plate affords straight guide surface sections 95 and 97 merging smoothly with a reversely curved guide surface section 99.

The underside of the plate '78 is provided with a number of recesses 96 in which are set permanent magnets 98 secured in position by screws ltltl, the magnets being located directly over the metal strips 52 embedded in the plate 36 of the base section 34-.

Referring particularly to FIG. 1, the plastic bags to be stacked, designated 102, are identical and comprise a lower ply of plastic sheet material 104-, an upper ply of plastic sheet material res, a closed trailing edge 198, a closed side edge lit), a closed side edge 112, a leading edge 114, an opening at 116, and cross slits 118. It will be understood, of course, that other articles may be stacked by the apparatus, for example, fiat sheets of a single thickness, bags with bottomand/or :side gussets, etc.

In the use of the apparatus, the bags are fed horizontally over the plate 82 (as indicated by the arrow) onto the upper tray section 76. The side edge moves along the guide surf-ace section 95, and before the leading edge 114- of the bag reaches the abutment surface 39, the bag is cammed toward the abutment surface 49 by reason of one corner thereof moving along the reversely curved guide surface section 99. Simultaneously, the inclined guide surface 4-8 cams the edge 112 of the bag downwardly, and the bag finally comes to rest between the rail 38 and plate 32, as in FIG. 6, and between plates 57 and )d, as in FIG. 5. The openings 49 in the rail 38, the openings as in the plate 33, and the openings St? in the "plate 47 help to regulate the air under the bag which is in the course of being delivered so as to allow it to settle rapidly enough to be out of the way of the following bag. At the same time, the openings aforesaid restrict the escape of air so as to allow a bag which is in the course of being delivered to float into its approximate final position. The entire stacking tray is vibrated by the vibrator unit 28 during the stacking operation to facilitate movement of the bags one by one onto the stack and to their final positions. In addition, the stacking tray is tilted toward the abutment surfaces 39 and 42 so that the bags tend to move toward one corner of the tray. Sometimes it is found desirable to tilt the stacking tray toward the abutment surfaces 88 and 45. In addition, the bags may be fed over the plate 32, with an edge other than the edge 114 leading. For example, it may be desir-abie to make edge lit? the leading edge, in which event the edge lid engages with the abutment surface 49.

In its final position, each bag 1&2 rests with its leading edge 114 against the abutment surface 39 and with its edge 112 against the abutment surface 49. When the desired number of bags have been stacked, the operator may, without interrupting operation in any way, grasp the stack of bags by the fore corners thereof and remove it from the stacking tray, whereupon it is transferred to and mounted upon a wicket. Referring particularly to FIG. 9, it will be observed that the corners of the upper tray bottom 78, cut away as shown, afford recesses overhung by the corners of the stack and into which the fingers of the operator may be inserted to facilitate grasping the stack.

The base and upper tray sections, it will be observed, are held in position relative to one another by the permanent magnets 98 overlying the metal strips 52. When it is desired to change over from the stacking of one size of bags to the stacking of a difierent size of bags, it is merely necessary to remove the upper tray section "76 and to substitute therefor'an upper tray section of suitable size.

It will be understood, of course, that the present invention, as described and shown, is susceptible to various changes and modifications which may be made without any departure from the general principles or real spirit of the invention. Accordingly, it is intended to claim the present invention broadly, as well as specifically, as indicated in the appended claims.

Having thus described our invention, we claim as follows:

1. In a stacking device for sheet material, a tray includinga bottom for supporting sheets of material fed horizontally over the head end of said tray and stacked sheet by sheet upon said bottom, means carried by said bottom and affording a pair of abutment surfaces normal thereto, said abutment surfaces being disposed respectively at the foot end and on one side of said tray for engaging respectively with two adjacent sides of said stack, and means carried by said bottom and attending an upright guide surface opposite said abutment surface on the side of the tray, said upright guide surface including laterally offset sections respectively at opposite endscf said guide means joincdfby an intermediate section disposed for guiding said sheets of material as they move onto said stack, said ofiset sections lying in substantially parallel planes, said bottom being tilted slightly upwardly from the corner thereof at the foot end and on said one side of the tray, and means for vibrating said tray thereby to urge said sheets of material toward said corner for being stacked there against said abutment surfaces.

2. In a stacking device for sheet material, a tray ineluding a bottom for supporting sheets of material fed iii horizontally over the head end of said tray and stacked sheet by sheet upon said bottom, means carried by said bottom and affording a pair of abutment surfaces normal thereto, said abutment surfaces being disposed respectively at the foot end and on one side of said tray for engaging respectively with two adjacent sides of said stack, and means carried by said bottom and alfording an upright guide surface opposite said abutment surface on the side of the tray, said upright guide surface including laterally oifset sections respectively at opposite ends of said guide means joined by an intermediate section disposed for guiding said sheets of material as they move onto said stack, and the section of said upright guide surface at the foot end of said tray and the opposite abutment surface being spaced from each other a distance just sutficient to accommodate said sheet material, said bottom being tilted slightly upwardly from the corner thereof at the foot end and on said one side of the tray, and means for vibrating said tray thereby to urge said sheets of material toward said corner for being stacked there against said abutment surfaces.

3. in a stacking evice for sheet material, a. tray including a bottom for supporting sheets of material fed horizontally over the head end of said tray and stacked sheet by sheet upon said bottom, means carried by said bottom and affording a pair of abutment surfaces normal thereto, said abutment surfaces being disposed respectively at the. foot end and on one side of said tray for engaging respectively with two adjacent sides of said stack, and affording an inclined surface for guiding said sheets of material as they move onto said stack, and means carried by said bottom and afiording an upright guide surface opposite the means affording said inclined guide surface, said upright guide surface including laterally spaced offset sections respectively at opposite ends of said guide means joined by an intermediate section disposed for guidin said sheets of material as they move onto said stack, and the section of said upright guide surface at the head end of said tray and the means affording said inclined guide surface being spaced from each other a clear distance just sufficient to accommodate said sheet material, a support stand below said bottom, a ball and socket joint coupling said bottom tosaid stand for limited movement of the bottom relative to the stand so that the bottom may be tilted slightly upwardly from the corner thereof at the foot end and on said one side of the tray, and means for vibrating said tray thereby to urge said sheets of material toward said corner for being stacked there against said abutment surfaces.

4. In a stacking device for sheet material, a tray including upper and lower bottoms for supporting sheets of material fed horizontally over the head end of said tray and stacked sheet by sheetupon said upper bottom, said upper bottom overlying said lower bottom, cooperating magnetic members on'said bot-toms providing for adjust- :ability of said upperbottom relative to said lower bottom, means carried by said lower bottom and affording 'a pair of abutment surfaces normal thereto, said abutment surf-aces being disposed respectively at the foot end and on one side of said tray for engaging respectively with two adjacent sides of said stack, said tray being tilted slightly upwardly from the corner thereof at the foot end and on said one side of the tray, means providing a recess underlying a corner of said stack, said recess being adapted for receiving the fingers of the operator to facilitate grasping the corner of the stack, and means for vibrating said tray thereby to urge said sheets of material toward said corner for being stacked there against said abutment surfaces.

5. In a stacking device for sheet material, a sectional tray including a base section having a horizontally er:- tending bottom, an upper section having a horizontally extending bottom overlying and adjustably affixed to the bottom of said base section for supporting sheets of material fed horizontally over the head end of said tray and stacked sheet by sheet upon the bottom of said upper section, said base and upper section bottoms being of substantially the same size and means carried by the bottom of said base section and afiording a pair of abutment surfaces normal to the bottom of said upper section, said abutment surfaces being disposed respectively at the foot end and on one side of said tray for engaging respectively with two adjacent sides of said stack, said tray being tilted slightly upwardly from the corner thereof at the foot end and on said one side of the tray; and means for vibrating said tray thereby to urge said sheets of material toward said corner for being stacked there against said abutment surfaces.

6. In a stacking device for sheet material, a sectional tray including a base section having a horizontally extending bottom, an upper section having a horizontally extending bottom overlying and adjustably affixed to the bottom of said base section for supporting sheets of material fed horizontally over the head end of said tray and stacked sheet by sheet upon the bottom of said upper section, means carried by the bottom of said base section and affording a pair of abutment surfaces normal to the bottom of said upper section, said abutment surfaces being disposed respectively at the foot end and on one side of said tray for engaging respectively with two adjacent sides of said stack, and means carried by said bottom of the upper section and affording an upright surface, opposite said abutment surface on the side of the tray, or guiding said sheets of material as they move onto said stack, said tray being tilted slightly upwardly from the corner thereof at the foot end and on said one side of the tray, and means for vibrating said tray thereby to urge said sheets of material toward said corner for being stacked there against said abutment surfaces.

7. In a stacking device for sheet material, a rectangular sectional tuay including a base section having a horizontally extending bottom, an upper section having a horizontally extending bottom slidably seated upon the bottom of said base section for supporting sheets of material fed horizontally over the head end of said tray and stacked sheet by sheet upon the bottom of said upper section, and means conjointly providing a rim extending about said tray including means carried by the bottom of said base section and affording a pair of abutment surfaces normal to the bottom of said upper section, said abutment surfaces being disposed respectively at the foot end and on one side of said tray for engaging respectively with two adjacent sides of said stack, and means carried by the bottom of the upper section and affording a pair of upright surfaces, said upright surfaces being disposed respectively at the head end and on the other side of said tray for guiding said sheets of material as they move onto said stack, and the bottom of the upper tray being shaped to provide recesses for underlying the corners of said stack, said recesses being adapted for receiving the fingers of the operator inserted thereinto through gaps in said rim, means for tilting said tray upwardly from the corner thereof between said abutment surfaces, and means for vibrating said tray thereby to urge said sheets of material toward said corner for being stacked there against said abutment surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 1,236,892 Wilson Aug. 14, 1917 1,600,936 Eddleman, et a1 Sept. 21, 1926 1,694,638 Borrowdale Dec. 11, 1928 2,707,632 Daneke May 3, 1955 2,770,192 Mitchell etal Nov. 13, 1956 FOREIGN PATENTS 141,872 Australia June 27, 1951 

1. IN A STACKING DEVICE FOR SHEET MATERIAL, A TRAY INCLUDING A BOTTOM FOR SUPPORTING SHEETS OF MATERIAL FED HORIZONALLY OVER THE HEAD END OF SAID TRAY AND STACKED SHEET BY SHEET UPON SAID BOTTOM, MEANS CARRIED BY SAID BOTTOM AND AFFORDING A PAIR OF ABUTMENT SURFACES NORMAL THERETO, SAID ABUTMENT SURFACES BEING DISPOSED RESPECTIVELY AT THE FOOT END AND ON ONE SIDE OF SAID TRAY FOR ENGAGING RESPECTIVELY WITH TWO ADJACENT SIDES OF SAID STACK, AND MEANS CARRIED BY SAID BOTTOM AND AFFORDING AN UPRIGHT GUIDE SURFACE OPPOSITE SAID ABUTMENT SURFACE ON THE SIDE OF THE TRAY, SAID UPRIGHT GUIDE SURFACE INCLUDING LATERALLY OFFSET SECTIONS RESPECTIVELY AT OPPOSITE ENDS OF SAID GUIDE MEANS JOINED BY AN INTERMEDIATE SECTION DISPOSED FOR GUIDING SAID SHEETS OF MATERIAL AS THEY MOVE ONTO SAID STACK, SAID OFFSET SECTIONS LYING IN SUBSTANTIALLY PARALLEL PLANES, SAID BOTTOM BEING TILTED SLIGHTLY UPWARDLY FROM THE CORNER THEREOF AT THE FOOT END AND ON SAID ONE SIDE 